A fluorinated ester compound having all of C—H portions in a hydrocarbon compound fluorinated to C—F is useful as e.g. a precursor of a fluororesin material. As a method of fluorinating a hydrocarbon compound containing C—H, a method of using cobalt trifluoride, a method of direct fluorination by using fluorine (F2) and a method of carrying out a fluorination reaction by electrolysis of hydrogen fluoride in an electrolyzer (hereinafter referred to as ECF method), have been known.
In a case of carrying out a fluorination reaction by using fluorine in a liquid phase, in an ordinary case, a solvent which does not react with fluorine but dissolves fluorine (such as a solvent consisting of a perfluoro compound) is used as a reaction solvent to form the liquid phase. As a reaction solvent employed in a conventional method, a chlorofluorohydrocarbon such as CCl2FCClF2 (hereinafter referred to as R-113) or a fluorine type solvent such as a perfluorohydrocarbon or chloroperfluoropolyether (JP-A-4-500520) may be mentioned. Among these solvents, a chlorofluorohydrocarbon has a high ozone depletion potential and thus its production is limited, and it will be no longer available in future. Further, the hydrocarbon compound used as a substrate in the fluorination reaction in many cases has a low solubility in a solvent, whereby the fluorination reaction is carried out at an extremely low concentration, thus leading to a problem of poor production efficiency or a problem such that the reaction is carried out in a suspension system which is disadvantageous to the reaction.